Electrical heating unit.



F. KUHN.

ELECTRICAL HEATING UN-IT.

APPLICATION FILED JUNE 28,1913.

1,170,166. I Patented Feb. 1, 1916.

In T677 tar 271172,? 23 /7 :0

, 'tive view of the element; Fig. 2 is a longi'-' STATES PATENT OFFICE. 1

FRANK KUHN, OF DETi-OIT, IICHIGH.

amen-mar. m'rms um'r.

Specification of Letters Patent.

Patented Feb. 1, 1916.

Application fled June 88, 1818. Serial ll'o. 778,855.

To all whom it may concern:

Be it known that I, FRANK KUHN, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Electrical Heating Units, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to electrical heating units and is more particularly designed for use in air heaters.

It'is the primary object of the invention to provide suflicient means for dissipating the eat or communicating the same to the air and which will avoid the heating element. I

To this end the invention comprises the construction as hereinafter set forth.

In the drawings: Figural is a perspechigh temperature in tudinal section therethrough; and Fig. 3 is a cross section.

In the construction of electrical heating units, it is desirable to incase the resistor in an armor serving the double purpose of protection against short circuit and mechanical stresses, and also a means for uniformly distributing the heat. Where it is desired produce vradiant heat-as, for instance, 1n broilers, toasters, etc.,-a higher tempera ture is required in the heat-distributing surface than for the heating of liquids or gases. It is, however, desirable in the construction of air heaters to limit the size of the a paratus, and it is difficult to produce the esired efiiciency without raising the temperature of the heat-distributing surface to-a higherpoint than desirable. With my improved construction I obtain the desired result by greatly increasing the extent of the heatdistributing surface without materially increasing the space limits within which the unit is confined. I further obtain this increased heating surface, preferably by forming it as an integral part of the armor which protects the unit, so as ,to secure the best eat conduction.

In detail, A is the heating resistor, which,

as shown, is wound upon a flat insulated core member B and has its opposite ends attached to terminal contact pins C.

,junction 1 will dissipate the heat or communicate it to D is a metallic armor for incasing the resistor, being insulated therefrom by intersheets of insulation E, of mica or other suitable material. The armor is formed of flat st 'ps of metal lying adjacent totheinsulatedresistorandhavingtheir secured by crimping over, as atF, or in any other smtable seam connection.

To increase the extentof heat-radiating surface, each of the opposite plates D' an D of the armor is crimped or folded to form outwardly-extending, integral returnbent flanges G, which, as shown, extend rpendicular to the plane of the unit. me 11 being continuous with the portions of e armor in direct contact with the heat generator, will rapidly conduct the heat outward, and the extended surface in conwith the directly heated surface a larger volume of air than would be possible with a plain armored surface.

The unit constructedas described may be arranged in an convenient manner within a su porting ame or housing, and W111 divi e the space therein into a lar number of air passages in proximity to e heating surface.

What I claim as my An electrical hea unit, comprising a comparativel'nglait atedhnresisto' 5' extend-' inglo'tu yina eanacomparativ g y flat, longitudinally extending armor, incasing said resistor, said armor having'portions lying in planes parallel to the resistor and in heatconducting contact with the flat face thereof and being also provided with integrally formed outward ex tensions positioned crosswise to the plane of the resistor and at substantially right angles thereto, sai outward extensions being distributed alorgstthle l ngth f iaid remstor to form heat "bu aces.

invention is:

in prese ce of two witn 'Wi: I

June P. Bun; Hun

e 0 ting ant-' 

